1. Field of the Invention
The field of the invention is data processing, or, more specifically, methods, apparatus, and products for token-based flow control of messages in a parallel computer.
2. Description of Related Art
The development of the EDVAC computer system of 1948 is often cited as the beginning of the computer era. Since that time, computer systems have evolved into extremely complicated devices. Today's computers are much more sophisticated than early systems such as the EDVAC. Computer systems typically include a combination of hardware and software components, application programs, operating systems, processors, buses, memory, input/output devices, and so on. As advances in semiconductor processing and computer architecture push the performance of the computer higher and higher, more sophisticated computer software has evolved to take advantage of the higher performance of the hardware, resulting in computer systems today that are much more powerful than just a few years ago.
Current parallel computers are running a number of processes that just a few years ago would have seemed unimaginable. For example, current parallel computers may execute millions of processes simultaneously. Processes executing on compute nodes in the parallel computer often send each other data. The flow control of that data is not always even. That is, some destinations receive more data than others. If a particular destination receives more data that it can process, efficiency is harmed for that destination as well as senders of the data.